Answer to Question #2674 Submitted to "Ask the Experts"
Category: Radiation Workers
The following question was answered by an expert in the appropriate field:
I just found out I am pregnant, only two or three weeks. I work in a cardiac catheterization lab where my job is to scrub in with the cardiologist and be at the table side. This is one of the highest-dose areas in the room. I want to keep in good standing at my job and keep working and doing cases. As long as I wear my fetal badge, will I be okay or should I look for a different job? I have seen radiologists do fluoroscopy cases while pregnant but I have never seen a female cardiologist. I'm looking for some suggestions and advice. I haven't even received my fetal monitor badge yet. Like I said, I just found out.
You are correct that standing next to the table during cardiac fluoroscopy procedures is one of the highest-dose areas in the room. But you also mention a couple of things that lead me to believe we have no reason for concern. One thing you mention is that you'll be getting a fetal monitor badge, presumably to wear at your waist, under your apron. This is the best way to be sure of the exposure received by the fetus. It also suggests that you are probably wearing a radiation badge to monitor your personal exposure—maybe you wear it at the collar outside the lead apron?
If you do wear a radiation badge at the collar outside your lead apron, you can roughly estimate fetal exposure since a lead apron will stop 95–98% of the radiation which means that only 2–5% of the scattered x rays get through to the abdomen. So, for instance, if your collar badge had a reading of 1 mSv for a month, then we could estimate that your abdomen under the apron received 0.02–0.05 mSv and the fetus even less than that because your abdominal tissue offers some shielding (mSv or millisievert is a unit of effective radiation dose). If you don't wear a collar badge, it is still important to note that the lead apron you wear stops virtually all of the radiation to your abdomen.
In my experience (20 years) at a medical institution with nearly 1,000 cardiac lab and radiology staff members, we have not had a reading above zero on the fetal badge (the badge worn at the abdomen under the apron) of a pregnant worker regardless of the duties performed by the mother. The fetus of a woman working in cardiology or radiology is not at greater risk of birth defects as long as standard radiation precautions are followed (minimizing time, increasing distance, using shielding) and exposure is kept within regulatory limits (5 mSv during gestation). Scientific evidence suggests that doses below 50 mSv to the fetus will not measurably increase the risk of birth defects or miscarriage.
I can offer a sometimes overlooked pointer that might help reduce your dose: your primary source of radiation is coming directly from where the radiation beam is interacting with the patient—in your case, directly from the chest near the heart. Even if you need to stand next to the table to be immediately accessible for the cardiologist, if you can take an extra step or two down the length of the table toward the patient's feet, that increases your distance from the source and can reduce your exposure.
Certified Medical Health Physicist